According to Eric Giguere, Google is preparing to roll out an API for AdSense that will allow site owners to share revenue with individual members. For example, if YouTube ran AdSense ads and a user posted a popular video, YouTube could automatically share some of its ad revenue with that member. Though revenue-sharing on user-content-driven web sites is nothing new, an API from Google could simplify the process immensely, which may prompt current AdSense members to give it a try. The API isn't widely available yet, but after RateItAll.com leaked news of the system in a press release yesterday, Google's Shirin Oskooi made an official announcement
on the Inside AdSense blog.
[Via John Battelle's Searchblog